I want to know if there exists an insurance for bug invassion. We all know that if we have a wood house, and it has termites, we should probably have to make serious investments or worse , rebuilt the house.

The best insurance for termites is frequent inspections.

Generally "vermin" which includes bugs, bees, termites, ants, etc. is a specific EXCLUSION on every insurance policy I've ever seen in my 30+ years in the business.

Many exterminator companies will offer some kind of guarantee (aka-insurance) with their service. I think that's the best you'lll find.